SplFileObject::flock
(PHP 5 >= 5.1.0, PHP 7)
SplFileObject::flock — Portable file locking
说明
public SplFileObject::flock
( int
$operation
[, int &$wouldblock
] ) : boolLocks or unlocks the file in the same portable way as flock().
参数
-
operation -
operationis one of the following:-
LOCK_SHto acquire a shared lock (reader). -
LOCK_EXto acquire an exclusive lock (writer). -
LOCK_UNto release a lock (shared or exclusive). -
LOCK_NBto not block while locking.
-
-
wouldblock -
Set to
TRUEif the lock would block (EWOULDBLOCK errno condition).
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE。
范例
Example #1 SplFileObject::flock() example
<?php
$file = new SplFileObject("/tmp/lock.txt", "w");
if ($file->flock(LOCK_EX)) { // do an exclusive lock
$file->ftruncate(0); // truncate file
$file->fwrite("Write something here\n");
$file->flock(LOCK_UN); // release the lock
} else {
echo "Couldn't get the lock!";
}
?>
更新日志
| 版本 | 说明 |
|---|---|
| 5.5.22, 5.6.6 |
Added support for the wouldblock parameter on
Windows.
|
| 5.3.2 | The automatic unlocking when the file's resource handle is closed was removed. Unlocking now always has to be done manually. |